[lustre-devel] [PATCH 10/11] lustre: ldlm: checkpatch cleanup

From: Degremont, Aurelien <degremoa@amazon.com>
To: lustre-devel@lists.lustre.org
Subject: [lustre-devel] [PATCH 10/11] lustre: ldlm: checkpatch cleanup
Date: Thu, 25 Jul 2019 08:07:59 +0000	[thread overview]
Message-ID: <ACCFCCDF-B63A-40A9-8992-A8959FD94079@amazon.com> (raw)
In-Reply-To: <alpine.LFD.2.21.1907250246001.19895@casper.infradead.org>

?Le 25/07/2019 03:54, ? James Simmons ? <jsimmons@infradead.org> a ?crit :

    > Le 24/07/2019 05:38, ? lustre-devel au nom de James Simmons ? <lustre-devel-bounces at lists.lustre.org au nom de jsimmons@infradead.org> a ?crit :
    >     
    >     From checkpatch - "ENOSYS means 'invalid syscall nr' and nothing else"
    >     So using ENOSYS is no no. We get away with this because people rarely
    >     actually handle each error code individually.
    > .
    >     
    > As a general comment about this, I think we should improve this in the futur. Some people asked me "what's the error code when this or that happens in Lustre?". And I've got no real answer for that.
    > Indeed people, most of the time, only checks returned code against 0. That does not help when looking at specific Lustre issues.

    perf probe 'lustre_function%return $retval'

    Does the same thing as lctl set_param debug=+trace except dynamic probes 
    can work on any kernel function without code modification!!!

I mean from userspace.
When some applications want to adapt its behaviour depending on what is happening in Lustre. 